Regardless of increased level caps, there is no T6. T5 is it, and I do believe the devs have even said so at some point. Why would they release all these "refit" T5 ships that everybody wanted for endgame if they are just gonna have another tier of ships? Not to mention there are no T6 skills, the skill tree maxs out at T5, we just get more points to spend as they increase the lvl cap, the reason being that originally the game was not supposed to have a skill point cap.
There's a dev post around here somewhere showing level 61 Fleet Admiral rank and possible T6 ships listed at that level.